Typewriting machine



L. c. MYERS TYrEwRITING MA'cHINE Filed laren s. 193s Sept. 10, 1940.

2 Sheets-Shear 1 INVENTOR ATTORNEYS Sept. 10, 1940. c. MYERS 2,214,414

TYPEWRITING MACHINE Filed latch 9, 195B 2 Sheets-Sheet 2 4 ATTORNEYS Patented Sept. 10, 1940 UNITED STATES PATENT OFFICE TYPEWRITING MACHINE Lewis Cary Myers, Freeport, N. Y., assignor to Royal Typewriter Company, Inc., New York, N. Y., a corporation of New York Application March 9, 193s, serial No.,194,9z1

16 Claims.

dium where it is desirable to present, at the printing line, a complete new or unused portion of the transfer medium for each new line of typing, all though more particularly to means for forming negative imprints on a master sheet which is subsequently used for producing numerous duplicates.

In the co-pending application of George F.

Handley, Serial Number 170,451, led October 22,

1937, there is disclosed and claimed a ribbon feeding mechanism of this general class which is operable during each return movement of the carriage to feed a length of transfer medium or ribbon equal to the length of the line typed during the preceding carriage letter spacemovement.

An object of the present invention is to provide a typewriter or like machine ribbon feed mechanism which will feed a length of ribbon or strip equal to the previously typed line, and in which the arrangement of parts is more compact than in mechanisms of this general character hereto- 'fore known.

Another object is toprovide a mechanism of the kind referred to which is so constructed, and

0 adapted to be so mounted on a typewriter, that none of the parts extends beyond the normal limits of the main frame to an objectionable or disadvantageous degree.

A further object is to provide such a mechanism the parts of which are adapted to be mounted mainly on the typewriter or like machine carriage.

A still further object is to providemechanism of the character referred to and including a ribbon guiding device mounted for movement from its normal operating position to a position in which placement of the ribbon is facilitated.

Other objects will become apparent from a 5 reading of the following description, the appended claims, and the accompanying drawings, in which:

Figure l is a top plan view of a typewriting machine with some parts omitted and showing mech- 50 anism embodying my invention applied thereto;

Figure 2 is a front elevation thereof;

Figure 3 is a fragmentary view in plan and on an enlarged scale showing two cooperating feeding elements with a portion of a ribbon operative- ,55 ly engaged thereby.

Figure 4 is a vertical sectional view taken on the line 4-4 of Figure 1 and being drawn on an enlarged scale with some parts shown in elevation;

Figure 5 is a fragmentary detail view showing a matrix or work sheet interposed between the usual or conventional typewriter ribbon and a hectograph or other ribbon arranged to be fed in accordance with the invention;

Figure 6 is a fragmentary view in horizontal section taken on the line 6-6 of Figure 4 and 10 yshowing a means for freeing ribbon feed elements from operative engagement with a ribbon;

Figure 7 is a detail sectional view taken on the line 1-1 of Figure 6 and drawn on an enlarged scale';

Figure 8 is a fragmentary view in vertical section taken on the line 8-8 of Figure 1, drawn on an enlarged scale, and showing ribbon feed elements and drive mechanism therefor;

Figure 9 is a fragmentary View in vertical sec- 20 A tion taken on the line 9-9 of Figure 8 and showing a one-way drive device; and

Figure 10 is a fragmentary View in vertical section taken on the line I0l0 of Figure 8 and showing a feed roll check pawl and ratchet device.

The drawings show one embodiment of the invention asl applied to a Royal'standard typewriting machine, but it is to be understood that mechanism embodying the invention may be applied to other types of machines.

The machine shown in the drawings includes a stationary main frame A and a carriage generally designated B mounted on the main frame for reciprocatory movements in the usual manner, viz., an intermittent or step-by-step movement from right to left which is effected by a motor and an escapement mechanism actuated by the key levers or the space bar, and a return movement from left to right. Suchvan escape- 40 ment mechanism is shown, for example, in the Patent Number 1,212,939, issued January 16, 1917, to George F. Handley.

'I'he carriage includes the usual end plates l and 2 in which is journaled a platen 3, and also 45 mounted on the carriage are'the usual apron 4 and rollers 5, only one of which is shown (see Figure 5), for feeding a sheet of paper C forwardly in front of the platen and thence upwardly in front of the platen. Mounted on the carriage is a bail including spaced supporting arms 6-6 connected at their forward ends by a bar 1 having journaled thereon pressure rollers 8-8 for directing usual Work sheets rearwardly over the platen after they have passed above the printing line. The arms 6-6 extend from the cross bar 1 rearwardly over the platen and are pivotally connected as at 9-9 to the'upper ends of arms II0 which, in turn, are pivotally mounted as at II on the carriage end plates I, 2. (See Figure 4.) Springs I2-I2 interposed between the arms 6 and the carriage end plates urge the arms downwardly so as yieldably to hold the pressure rollers 8 against the platen.

Formed integrally with the end plate I is a laterally extending shelf I3 on which a combined line spacing and carriage return lever F is mounted and connected to the platen 3 in the usual manner. Two ribbon spools I4I4 are shown mounted on the main frame in the usual manner, the reversible `inking ribbon I5 being adapted to be unwound from one of the spools I4 and wound upon the other, as is customary.

The typewriting machine as thus far described is not claimed per se as constituting the present invention, it being understood that the invention comprises parts to be hereinafter described and combinations of such parts with each other and with the known typewriting machine construction already described.

Although the invention is not necessarily restricted to the use of ribbon feed mechanism adapted to be mounted on or applied to type- Writing machines of standard or known construction, it is desirable in many cases to apply the feed mechanism to such machines, and for the purposes of illustration the drawings show an embodiment which may be fitted compactly to a machine of known construction without substantially increasing the over-all size of the machine and without its being necessary to alter the machine structure in any material respect.

In the form shown, a roll ribbon supply generally designated D is mounted at the left hand end of the carriage, and the hectograph or other transfer medium ribbon I6 is arranged to be fed from the roll along the printing line of the platen in a manner to be described. In order to protect the master sheet C and to prevent it from being marred by the ribbon I6, a pair of spaced guards I1 is adjustably mounted on the bail bar 1, being held in adjusted position on the bar by means of screws I8, as more fully explained in the co-pending application of George F. Handley, Serial Number 170,451, previously referred to.

The ribbon supply means D includes a mounting plate I9 the major portion of which lies in a horizontal plane but which is provided with a vertical attaching flange 20 which is secured to the carriage end plate I by means of a nut 2l having threaded engagement with a sleeve 22 fixed to and extending outwardly to the left from the carriage end plate. The sleeve 22 acts as a bearing for a platen extension shaft 23 a portion of which is shown in dotted lines in Figure 1. The shaft 23 is provided with the usual knurled knob 24 for rotating the platen. An extension bar 25 connected to the carriage end plate y I is connected by means of a screw 26 to a vertically extending ear or flange 21 formed integrally with the mounting plate I9 for supporting the mounting plate at its outer end.

A ribbon spool 28 containing the wound-up supply of ribbon is journalledas at 29 on the mounting plate I9, a knurled nut 30 serving to hold the spool in place and to adjustably tension it against a spring friction device 3|. Ribbon I6 is led from the spool over idlers 32 and 33 and thence along the printing line of the platen. Preferably the idlers 32 and 33 are so mounted as to facilitate threading or placement of the ribbon, and in the form shown the idler rolls are mounted in spaced relation on a movable support or plate 34 which is pivoted to the mounting plate I9 as at 35. A spring 36 interposed between an extension 31 on the mounting plate and an ear 38 struck up from the plate 34 urges the plate to the position shown in full lines in Figure l, wherein the roller 33 is positioned to locate the ribbon AI6 along and in cooperative relation to the platen 3. A stop 39 located on the mounting I plate I9 is positioned to be engaged by the movable supporting plate 34 so as to limit the movement thereof under the urge of the spring 36 and bon. Preferably a stop 4I is arranged to extend'- up from the plate I9 for limiting the outward movement of the plate 34.

The support plate 34 is movable to a position to locate the idler roller 33 relatively close to the printing line of the platen for holding the ribbon close to the platen, as shown in full lines in Figure 1, and is movable to another position, as shown in dotted lines in Figure 1, to locate the idler roller 33 relatively far from the printing face of the platen to facilitate placing the ribbon around the idler roller. It will be observed that the support 34 is movable bodily substantially in a plane containing the platen axis and the printing line. The spring 36 is active when the support is in either of these positions for urging it to the position in which the idler roller 33 is close to the printing line of the platen.

Referring now to the means generally designated E for feeding the ribbon I6, preferably there is provided a mounting bracket generally designated 42 which includes a horizontal upper plate part 43 and a. horizontal lower plate part 44 connected by a vertically extending plate part 45. The vertical plate part 45 is formed with an upper extension 46 secured to a stud 41 on the carriage end plate 2 by means of a. screw 48, and is further formed with a lower extension 49 which is secured to a stud 50 on the carriage end plate by means of a screw 5I, thus firmly connecting the entire bracket 42 to the carriage. At the extreme outer end of the upper plate part 43, an upturned flange 52 serves to journal a platen extension shaft 53 provided with the usual knurled knob 54.

Mounted on the bracket 42 is a pair of feed roll elements 55 and 55a which preferably are formed with teeth or serrations normally adapted to inter-mesh and to grip between them the free end of the ribbon I6, the feed rollers being rotated in a manner to be described so as to feed the ribbon from left to right relatively to both ythe carriage and the main frame, as viewed in Figures 1 and 2. The feed roller 55 is secured to a shaft generally designated 56 by means of a nut 51. The shaft is formed with a relatively large central portion 58 and a relatively reduced diameter upper end portion 59 providing, between the shaft portions 58 and 59, a. resultant shoulder 6U, the nut 51 securely clamping the roller 55 against the shoulder so that the roller will rotate in unison with the shaft (see Figure 8). The enlarged central shaft portion 68 is iournaled in an aperture 6| formed in the upper plate part 48, and below the enlarged shaft portion 58 is a reduced end portion 62, a resultant shoulder 68 intervening between the shaft portions 58 and 62. A one- -way drive connection or feed ratchet wheel 64 is mounted on the shaft portion 62 and is held against the shoulder 63 by means of a check ratchet 65 formed with a sleeve hub 66 extending through an aperture 61 in the lower plate part 44 and being drawn up tight by a nut 68 on the extreme lower end of the shaft portion l62. Thus the feed roll 55, the check ratchet 65, and the one-way drive or feed ratchet. wheel 64 are all securely connected to and rotatable in unison with the shaft 56.

A toothed sprocket wheel element 68 is mounted on the enlarged shaft portion 58 so as to be freely rotatable with respect to the shaft. Secured to the sprocket 89 is a disc 18 which is provided with a pawl 1I pivoted to the disc at 12 and urged into engagement with the one-way drive ratchet 64 by means of a spring 13. Thus, when the sprocket 68 is rotated in a clockwise direction as viewed in Figure 9, the pawl 1I will drive the ratchet wheel 64 and consequently will rotate the shaft 56 and the feed roller 55. In order to prevent reverse rotation of the feed roller 55, a pair of check pawls 14 are pivoted as at 15 on the lower plate part 44 and are urged into engagement with the check ratchet 65 by means of springs 16, the pawls and check ratchet teeth being so disposed as to prevent counter clockwise rotation of the shaft 56 as viewed in Figures 9 and- 10. Thus the arrangement is such that, when the sprocket is rotated in the clockwise direction as viewed in Figure 9 and as viewed when looking down on Figure 1, the feed roll 55 will be rotated with the sprocket, but, when the sprocket is rotated in a counter clockwise direction, the pawl 1| will ride over the teeth of the ratchet 64, and the pawls 14 will engage the teeth of the check ratchet 65 to prevent rotation of the feed roll. When the feed roll 55 is rotated in the manner just described, it will rotate the feed roller 55P- with which it intermeshes, and the ribbon I6 will be fed between the rollers from the left to the right relatively to the platen, as viewed in Figure 1.

Preferably, the feed roller 55a is so mounted as topermit its being disengaged from the feed roller 55 so as to facilitate placing the free end of the ribbon I6 between the two feed rollers. In the form shown, the feed roller 65a is journaled upon a shaft 11 with respect to which it is freely rotatable, and is prevented from being displaced upwardly from the shaft by means of a nut 18. The lower end of the shaft extends through a slot 18 formed in the plate part 43 and is secured as at 60 to one arm 8l vof a threearmed lever generally designated 82 which is pivoted as at 83 to the platepart 43. A spring 84 interposed between an arm 85 of the threearmed lever and a stud 86 on the plate part 43 urges the lever to a position to effect operative engagement of the feed vrolls 55 and 55B. An adjustable stop screw 81 is carried by an ear 88 formed on the plate part 43, and is adapted to engage the arm for limiting movement of the three-armed lever under the urge of the spring 84; and a lock nut 88 serves to lock the stop screw 81` in adjusted position. A feed roll releasing or operating lever 88 is pivoted as at SI and is formed with a cam toe 92 engageable with the three-armed lever for swinging the latter to the position shown in dotted lines in Figure 6 against the urge of the spring 84 for effecting disengagement of the feed rollers 56 and 66". In accordance with an important feature of the invention, means adapted to be mounted on the carriage compactly is provided for operating the sprocket 68 so as to actuate the feed rolls. A flexible drive means or track, in the form shown a chain 83, is wound upon a spring actuated take-up barrel 84 journaled as at 86 on the bracket '42, a spring 86 constantly urging the barrel in "take-up direction, that is, in a clockwise direction as viewed in Figure 1. The unwound end of the chain extends transversely to the direction of movement of the carriage along a stretch 91, and is then passed .around and in operative engagement with a portion of the sprocket 68, the extreme end portion of the chain extending along a stretch 88 which is substantially parallel to the direction of carriage travel and being anchored to a bracket 88 secured to the main frame. Thus the chain engages the sprocket intermediate the take-up barrel and the connectionl of the unwound endV of the chain to the bracket 88 on the main frame. In operation, and with the assumption that the carriage is at the right hand end of its travel preparatory to the typing of a line, the machine will be operated in the usual manner for typing upon the master sheet C. During the typing or letter space movement of the carriage, the chain 83 will be wound up or retrieved by the barrel 84, and will travel past and ei'fectrotation of the sprocket wheel 68 in a direction such that the pawl 1I, which is rotatable in unison with the sprocket, will ride over the teeth on theratchet 64, whereby the ratchet 64, the shaft 56, and, consequently, the feed rolls 55 and 55L will not be rotated, and rotation of the feed rolls during the letter spacing movement of the carriage will be positively prevented .by the check pawls 14 cooperating with the check ratchet 65. However, during the return movement of the carriage from left to right after the typing of a line, the chain will be unwound from or paid out by the take-up barrel so as to rotate the sprocket Wheel 68 in a direction to drive the shaft 56 through the pawl 1I and the ratchet wheel 64, thereby rotating the feed rolls 55 and 55*l and feeding the ribbon I6 to the right relative to the carriage.

The gearing for driving the feed rolls is such that, during return movement of the carriage, the ribbon I6 will be fed relatively to the carriage an amount bearing'a predetermined ratio to the previous letter spacing carriage movement, and,

e in the embodiment illustrated, the sprocket 68 is of the same eective pitch diameter as the feed roll 55, so that the ribbon I6 will be fed an amount exactly equal to the letter spacing movement of the carriage during the typing of the line just completed. In this way a completely new and unused portion of the transfer medium ribbon will be presented along the line of typing before the start of each new line, and the quality of reproduction upon the master sheet C therefore is enhanced. It will be observed that, during the letter spacing movement of the carriage, the ribbon I6 does not move relatively to the carriage, but does move relatively to the main frame, whereas, during the return movement of the carriage,lthe stretch of ribbon extending in front of the platen moves relatively to both the carriage and the main frame.

The typewriting machine disclosed herein embodies the invention in a preferredform, but it will be understood that various changes may be made in the construction and relative arrangefor movements in opposite directions and having a platen, a ribbon supply mounted on the carriage at one side of the platen, a pair of normally inactive feeding elements mounted on the carriage at the other side of the platen for engaging therebetween the free end of the ribbon and for feeding said ribbon lengthwise of and in front of the platen, and co` operating means between said feeding elements and the main frame for actuating said elements for effecting the feed of a length of the free end of the ribbon equal to the length of movement of the carriage in one direction, said means including a chain connected to said frame, a chain take-up means on the carriage, and a sprocket journaled on the carriage and meshing with said chain and having driving connection with one of said feeding elements.

2. In a typewriting machine, the combination with a main frame, of a carriage mounted thereon for movements in opposite directions and having a platen, a ribbon supply mounted on the carriage at one side of the platen, a pair of normally inactive feeding elements mounted on the carriage at the other side of the platen for engaging therebetween the free end of the ribbon and for feedingsaid ribbon lengthwise of and in front of the platen, and cooperating means between said feeding elements and the main frame for actuating said elements for effecting the feed of a length of the free end of the ribbon equal to the length of movement of the carriage in one direction, said means including a chain connected to said frame, a chain take-up means on the carriage, a sprocket journaled on the carriage and meshing with said chain, and a one-way drive connection between said sprocket and one of said feeding elements.

3. In a typewriting machine, the combination with a frame, of a carriage mounted thereon for movements in opposite directions and having a platen'; means mounting a ribbon supply on the machine; a ribbon feeding device mounted on the carriage and Abeing operable for drawing ribbon from said supply and feeding it relatively to the platen; and means for operating said feeding device during movement of the carriage in one direction comprising a take-up barrel journaled on said carriage, an elongated flexible drive member partly wound on said barrel and having its unwound end connected to the frame, and a one-way drive lconnection between said feeding device and the flexible drive member and engaging the latter intermediate said barrel and the connection of the flexible member to the frame.

4. In a typewriting machine, the combination with a frame of a carriage mounted thereon for movements in opposite directions and having a memberV partly Wound on said barrel and having its unwound end connected to the frame. and

one-way drive gearing between the feeding de- Y vice and the flexible drive member intermediate said barrel and the connection of the flexible member to the frame, the gearing providing a gear ratio such that, upon movement of the carriage in said one direction, the feedingdevice will be operated to feed the ribbon relatively tothe platen an emount equal to said movement of the carriage.

5. In a typewriting machine, the combination with a main frame of a carriage mountedthereon for movements -in opposite directions and having a platen; means mounting a ribbon supply on the carriage; a ribbon-feeding device mounted on the carriage;' a one-way Adrive connection including a sprocket for driving said device to feed ribbon relatively to the platen; a take-up barrel journaled on the carriage; and a chain partly wound upon said barrel and having its unwound end connected to said frame, thechain intermediate its frame-connected end and said barrel being in driving engagement with said sprocket. i

6. In a typewriting machine, the combination with a frame of a carriage mounted thereon'for movements in opposite directions and having a platen; means mounting a ribbon supply on the` carriage; a ribbon-feeding device mounted onA the carriage; a one-way drive connection including a sprocket for driving said device to feed ribbon relatively to the platen; a take-up barrel journaled on the carriage; and a chain partly wound upon said barrel and having its unwound end connected to said frame, the chain intermediate its frame-connected end and said barrel being in driving engagement with said sprocket, the effective pitch diameter of the sprocket being such that when the carriage is moved in one direction the feeding element will feed the ribbonrelatively to the platen an amount equal to said movement of the carriage.

'7. In a typewriting machine, the combination with a frame, of a carriage mounted thereon for movements in opposite directions and having a platen; means mounting a ribbon supply on said carriage; two coacting feed rolls journaled on the carriage and between which the ribbon is trained;- and means for driving said feed rolls during movement of the carriage in one direction for feeding the ribbon relatively to the platen comprising a sprocket connected to one of said feed rolls, a take-up barrel journaled on said carriage, and a chain partly Wound on said barrel and having its unwound end connected to said frame, said chain intermediate its frame-connected end and the barrel being in driving connection with said sprocket.

8. In a typewriting machine, the combination with a frame. of a carriage mounted thereon for movements in opposite directions and having a platen; means mounting a ribbon supply on said carriage; two coacting feed rolls journaled on the carriage and between which the ribbon is trained; and means for driving said feed rolls during movement of thel carriage in one direction for feeding the ribbon relatively to the platen comprising a sprocket, a one-way drive connection between said Sprocket and one of said feed rolls, a take-up barrel journaled on said carriage, and a chain partly wound on said barrel and having its unwound end connected to said frame, said chain intermediate its frame-connected end and the barrel being in driving connection with said sprocket.

9. In a typewriting machine, the combination with a frame, of a carriage mounted thereon for movements in opposite directions and having a platen; means mounting. a ribbon supply on said carriage; two coacting feed rolls journaled on the carriage and between which the ribbon is trained; and means for driving said feed rolls during movement of the carriage in one direction for feeding the ribbon relatively to the platen comprising a-sprocket connected to one of said feed rolls, a take-up barrel journaled on said carriage, and a chain partly wound on said barrel and having its unwound end connected to said frame, said chain intermediate its frameconnected end and the barrel being in driving connection with said sprocket, the unwound portion of said chain having a stretch extending substantially in the direction of movement of the carriage and a stretch extending substantially transverse to the direction of movement of the carriage.

10. In a typewriting machine, the combination with a frame, of a carriage mounted thereon for movements in opposite directions and having a platen; means mounting a ribbon supply on the carriage at one end of the platen; a feed roll journaled on the carriage adjacent to the other end of the platen, the ribbon extending from said supply longitudinally past the platen and in contact with said feed roll and adapted to be fed at a constant ratio with respect to the feeding movement of the feed roll; and means for rotating said feed roll at a speed to feed the ribbon along the platen an amount bearing a fixed ratio to the amount of movement of the platen in one direction, said means comprising a sprocket, a one-way drive connection between said sprocket and said feed roll, a chain mounted on the carriage and being connected to the frame l and having driving connection with said sprocket,

and means for paying out and retrieving the chain during movement of the carriage.

11. In a typewriting machine, the combination with a frame, of a carriage mounted thereon for movements in opposite directions and having a platen; means mounting a ribbon supply on the carriage; a ribbon feed device mounted on the carriage for engagement with the ribbon and adapted to always feed the ribbon relatively to the platen a predetermined amount for each predetermined amount of operating movement of the feed device; a drive chain connected to the frame; means for supporting the chain on the carriage and to yieldably tension the chain; and one-way drive means interposed between said feed device and the chain including a sprocket journaled on the carriage and having meshing engagement with said chain.

12. In a typewriting machine, the combination with a frame, of a carriage mounted thereon for movements in opposite directions; a platen on said carriage; means mounting a ribbon supply, the ribbon extending from said supply longitudinally along the platen; a pair of cooperating feed rollers between which the ribbon is gripped; a sprocket; a one-way drive connection between said sprocket and one of said feed rolls; a chain operatively engaging said sprocket; and means connecting said chain to said frame and said carriage and including means for paying out and retrieving said chain when the carriage is moved on the frame in one direction to effect relative movement between the chain and the sprocket `and thereby to effect rotation of the feed rolls and feeding of the ribbon by an amount bearing a predetermined ratio to the amount the platen has moved.

13. In a typewriting machine, the combination with a main frame; of a carriage frame including a platen and mounted for letter space and return -direction movements on the main frame; a ribbon supply; and means effective upon each return of theA carriage to present a fresh printed-line-length portion of the ribbon at the printing line, said means including feed rollers engaging said ribbon; a chain engaging said feed roller equipment and having one end anchored on one said frame and the other end supported on the other frame, and a sprocket connected to one of said rollers and meshing with said chain.

14. In a typewriting machine, the combina# tion with a main frame; of a carriage frame including a platen and mounted for letter space and return direction movements on the main frame; a ribbon supply; and means effective upon each return of the carriage to present a fresh printed-line-length portion of the ribbon at the printing line, said means including feed rollers engaging said ribbon; a chain engaging said feed roller equipment and having one end anchored on one said frame and the other end extended to and past said feed roller equipment; and means on the other frame constantly effective either to take up or to pay out the extended end of the chain accordingly as the carriage frame is moved in one direction or the other, and a sprocket connected to one of said rollers and meshing with the extended end portion of the chain.

15. In a typewriting machine, the combination of a carriage; a platen thereon; means mounting a ribbon supply on the carriage; and means for directing ribbon from said supply along the printing line of the platen, said means including two spaced idler rollers and a support therefor mounted on the carriage for movements towards and from the printing line substantially in a plane containing the platen axis and the printing line, in one position of the support one of said rollers being located substantially in line with the printing line of the platen and the other roller beng located forwardly of said printing line, and in another position of the support both rollers being spaced substantially forwardly of the printing line of the platen.

16. In a typewriting machine, the combination with a main frame element of a carriage element mounted thereon for movements in opposite directions and. having a platen; means mounting a ribbon supply on the carriage; a ribbon-feeding device mounted on the carriage; a one-way drive connection including a sprocket for driving said device to feed ribbon relatively to the platen; a take-up barrel journaled on said carriage element; and a chain partly wound upon saidbarrel and having its unwound end connected to said main frame element, the chain intermediate its unwound-connected end and said barrel being in driving engagement with said sprocket.

LEWIS CARY MYERS. 

